Preparation of alkyd resins from complex carboxylic acids prepared from solvent extracts



United States Patent PREPARATEON 0F ALKYD RESINS FRGM 00M- PLEXCARBQXYLIC ACIDS PREPARED FRQM SULVENT EXTRACTS Walter E. Kramer, Niles,and Louis A. Joe, (Jrystal Lake, EL, assignors to The Pure Gil Company,Qhicago, llh, a corporation of Uhio No Drawing. Filed Dec. 30, 1960,Ser. No. 79,541

3 @laims. (Cl. 269-22) This invention relates to alkyd resins preparedfrom complex high-molecular-weight, polynuclear, aromatic,alkylaromatic, heterocyclic, polybasic acids derived from selectedpetroleum fractions, which resins are characterized by their highsolubility in more common organic solvents, resistance against attack byalkali and acid environments, high self-plasticizing ability, superiordielectric properties, and suitability for wire coatings and similarapplications. More particularly, this invention relates to alkyd resinsprepared from diand polybasic acids derived from solvent extractswherein the extracts are used as a source of complex,high-molecular-weight, polynuclear, aromatic, alkylaromatic,condensed-ring heterocyclic nuclei for said acids, through metalationand carbonation reactions and the resulting acids are transformed intoalkyd resins.

The alkyd resins represent a large group of compounds defined aspolyesters of polyhydric alcohols and polycarbox lic acids oranhydrides, e.g., glycerol phthalic anhydride resins. According to TheTechnology of Plastics and Resins, P. Mason 1. (1957), the alkyd resins(glyptals) are usually prepared by an esterification reaction asillustrated by the following general equation:

Because both reactants are polyfunctional, the reaction illustrates thegrowth of a linear polymer by such interaction of functional groups. Thenature of the terminal groups in the chain is controlled by the relativenumber of moles of polybasic acid and polyhydric alcohol used for thereaction. When the acid is in excess, the majority of the terminalgroups will be carboxyl, and if the alcohol is in excess, the majorityof the terminal groups will be hydroxyl. Using a dicarboxylic acid and adihydroxy alcohol produces a linear, thermoplastic resin. It is known inthis art that resins of the type of cyclic lactides or lactones areformed through cyclization reactions and resins of the cross-linked ornetpolymer type are formed, the latter being of greater importance inthe field of industrial plastics. The latter type of resins are formedwhen a component, acid or alcohol, is chosen which is tIi-functional.Cross-linking is said to take place in two stages; in the first stage,normal chain growth proceeds by the mechanism of the foregoing reaction,that. is

Blfiifih? Patented @ct. 2?, 1964 the presence of an organic or inorganicmetal salt and small amounts of oxygen or air. A feature of thisinvention is the discovery that the reaction of polybasic acids derivedfrom solvent extracts and linoleic acid, or dehydrated castor oil, andglycerine in the presence of an organic or inorganic metal salt andsmall amounts of oxygen or air forms a superior wire coating enamel.

It becomes then a primary object of this invention to provide a newclass of alkyd resins.

An object of this invention is to provide a new class of alkyd resinsderived from dibasic and polybasic acids prepared from solvent extracts,obtained in the refining of mineral lubricating oils.

An object of this invention is to provide a new class of alkyd resinsprepared by the reaction of polyhydric alcohols and dibasic andpolybasic acids prepared from solvent extracts obtained in the refiningof mineral lubricating oils.

Another object of this invention is to provide a new class of alkydresins and a method of preparation by the reaction of polyhydricalcohols and dibasic and polybasic acids, with or without a fatty acidmodifier, said polybasic acids being derived from solvent extractsobtained in the solvent refining of mineral lubricating oils andfractions thereof conducted in the presence of an organic or inorganicmetal salt and small amounts of oxygen or air.

Still another object of this invention is to provide a new class ofalkyd resins prepared by reaction of polyhydric alcohols with dibasicand polybasic acid mixtures derived from the high-molecular-weight,complex, polynuclear, aromatic, alkylaromatic and/0r heterocycliccompounds present in solvent extracts.

These and other objects of this invention will become apparent or bedescribed as the specification proceeds.

The complex, polynuclear, high-molecular-weight alkylaryl, aryl, orheterocyclic polybasic acids used to prepare the resins of thisinvention are described in copending applications Serial Number 819,932,filed lune 12, 1959, now abandoned, and 79,661, filed December 30, 1960.Although the polybasic acids may be prepared by the various knownmethods in the prior art for converting aromatic materials to carboxylicacids, such as are described in said copending applications, usingsolvent extracts as starting materials, the technique set forth in saidlater application represents a preferred method of preparation becauseof the increased efiiciency of the process and the higher yields ofpolybasic acids of high purity that are obtained. The starting materialsfor the reaction are well known by-products of the solvent extraction ofmineral lubricating oils and are adequately described as those aromaticmaterials separated from mineral lubricating oils througha-esterification, and when about one-third of the free acid remains, orwhen the rate of linear esterification decreases, B-esterificationbegins resulting in a rapid decrease of the acid content and theproduction of a resin in'gelled or insoluble state. Thisfl-esterification is noted by the remarkable increases in molecularweight and decreases in solubility and fusibility of the product. I

This invention is based onthe discovery that the ability of diandpolybasic complex, high-molecular-weight acids, derived from solventextracts obtained in the solvent refining of mineral lubricating oilsand fractions thereof, to react with polyhydric organic compounds toform alkyd resins which exhibit high solubility, high chemicalresistance, have self-plasticizing ability, form superior coatings andhave excellent dielectric properties depends on and their fractions,i.e., those aromatics obtained in the manufacture and refining ofneutral oils and bright stocks during treatment with a selective solventdesigned to extract the predominantly aromatic materials from theparaffinic materials. Solvent extracts resulting from the treatment ofmineral lubricating oils for the purposes of separating non-aromatichydrocarbons (the rafiinate and finished oil) from the aromatichydrocarbons (the extract and waste product) may be used and arepreferred as starting materials.

Since the general process of refining mineral lubricating oils in whichsolvent extracts are obtained is Well known, it is only necessary forpresent purposes to describe a typical procedure for obtaining same andgive some examples by way of illustration.

In a typical operation, desalted crude oil is first charged to adistillation unit where straight-run gasoline, two grades of naphtha,kerosine, and virgin distillate are taken off, leaving a reduced cruderesidue. The reduced crude is continuously charged to a vacuumdistillation unit 3 4- where three lubricating oil distillates are takenoff as side possible to vary the characteristics of the extract andstreams, a light distillate is taken 01f as overhead, and rafiinateproducts considerably by adjustment of the a residuum is withdrawn fromthe bottom of the tower. amount of water present. A rafiinate ofrelatively low The residuum is charged to a propane-deasphalting unitviscosity index can be obtained by using a water solution whereinpropane dissolves the desirable lubricating Oil 5 of phenol during theextractign and a affinate of high constituents and leaves the asphalticmaterials. Atypical viscosity index can be obtained by using anhydrousvacuum residuum charge to the propane-deasphalting unit phenol.Following are the physical characteristics of may have an API gravity of129, viscosity SUS at 210 typical extract products, from lubricating oilstocks de- F. of 1249, flash 585 F., fire 650 F., OR. of 13.9 weightrived from various crude oils and other source hydro- P and m y be blackin 6010K The easpha ted oil carbon materials, which may be used inaccordance with may have an API gravity of 215 to 21.8", viscosity, thisinvention.

TABLE I Sources and Physical Characteristics of Solvent Extracts API Sp.Gr. Vis/ Vis/ Vis/ F. F. Iodine Percent Percent Ext. No. Crude SourceSolvent Grav. at10F. 100 F. 130 F. 210 I V.I. Pour Flash Fire QR. SulfurEast Tex 11.1 2. G0 1 15.4 12.6 2.27 14.6 15.4 13.7

Furlural 131 0 Chlorcx 12. 2 Nitro-heuzcne. 10.0 Propane- 14.4

cresol. Phenol 13.6 Chlorex 13.6 Phenol 8.9 Furt'ural 14. 9

Extract No. 41 was obtained in the production of 85 Vis neutral, has anaverage molecular weight of 300, and contained 76.8% aromatics (by thesilica gel procedure).

Extract No. 42 was obtained in the production of 150 Vis Bright Stock,has an average molecular weight of 590, and contained 86% aromatics, 14%saturates, 86.2% carbon, 11.4% hydrogen, and averaged 3.3 aromatic ringsper aromatic molecule.

Extract No. 43 was obtained in the production of 170 Vis neutral, has anaverage molecular weight 01340, contained 87.0% aromatics, 13%saturates, 86.4% carbon, 10.7% hydrogen and averaged 2.7 aromatic ringsper aromatic molecule.

Extract No. 14 was obtained in the production of 200 Vis neutral, has anaverage molecular weight of 340, contained 87% aromatics, and 13%saturates.

Extract No. 45 was obtained in the production of 160 Vis Bright Stock,contained 92% aromatics and 8% saturates.

SUS, 210 F. of 165-175, NPA color 6-7, flash 575 F., The solventextracts from lubricating Oils used as startfire 640 F., and OR. of1.7-2.0. The dcasphalted oil ing materials for this invention have thefollowing general and various lubricating oil distillates from thereduced properties and characteristics. crude are subjected to solventextraction for the separation TABLE H of non-aromatic from aromaticconstituents prior to use. Characteristic Rama Value The refined. oil orrafiinate from the extraction proc- Gravit' API D SL045 0 esses is usedper se, or as blending stock, for lubricating S HE TE n 0 95564 6 oils,and the solvent extract, predominating in complex a viscosiyt 6 F 5 000(6') aromatic constituents, is distinctively useful in accordance g, .J40 19 6 mventlon- Viscosity, SUS, 210 F. 200-1500 or example, a crudeOil from an East Texas field with Vicosit index 101 +39 an API gravityof 33.1 was topped to remove such light Pour g g? n +354) fractions asgasoline, naphtha, l-zerosine, and a light lubricolorp g eatingdistillate. The vacuum residue was a "reduced M 01 e ar g z g'j'zggycrude having a viscosity of 1251 SUS at 210 F., 2.2 per- 300) g a race 0e 320 750 cent sulfur, and an API gravity of 12.6. After propane- Z Ideasphalting, the oil had a viscosity of 174 SUS at 210 322: E3 5 O F.and an API gravity of 21.7. This deasphalted oil was sulfurg percent Wt5 treated with phenol to produce a raffinate from which an g ounds gaviation lubricating all could be prepared. The oil ex- Aromatics Epgcen W ro tracted by phenol treatment, after removalof phenol, is Thiocom S 0 mpoun s Q ready for use as the starting material in accordancewith Neutral z i 40 51 this invention. Y i

Solvents other than phenol may be used to obtain the 2 1 of rings/mean 17 3 5 extraction product used in accordance with this invention, H/C Mfgg g n O L 1 for example, liquid sulfur dioxide, nitrobenzene, Chlorex,H/C d i 'gg jgf chlorophenol, trichloroethylenc, cresylic acid,pyridine, H/C atom f i d}; 7 i I W furfural, or the Duo-Sol solution(comprising liquid proti 1.2 94509 pane and cresol) may be used. Whenusing phenol, it is Ne rest empirical formula C l-L C H The gravities ofthe extracts in general increase with increase in the viscosity of theraflinate at a constant viscosity index. Stated otherwise, the gravitiesof these extracts increase with decrease in viscosity index of therafinate at a constant viscosity. For the production of 100:5 V.l.neutral oils, the viscosities of the extracts increase with increase instated viscosities of the neutral oils (raffinates). The pour points ofextracts are high and are effected by changes in the depth ofextraction. The sulfur contents are also affected by the depth ofextraction. The solvent extracts are characteriezd by containingaromatic and sulfur compounds in the range of 70-90%, the remainderbeing principally saturates, or material behaving as saturates, togetherwith a minor pro-. portion of from 3.0 to 6.0% of organic acids. Theorganic acids present are not susceptible to extraction by the use ofaqueous strong caustic because of emulsion formation. Very littleasphaltic material is present in solvent extracts and they contain nomaterial volatile at room temperatures.

The materials shown in Tables I and II are merely illustrative and theinvention is not to be limited thereby.

It is apparent that the composition and characteristics of the acids, orresins prepared therefrom, will vary some- What depending on theconcentration and types of polynuclear aromatic hydrocarbons in thesolvent extracts used. In such complicated mixtures as solvent extractsfrom petroleum oils, and solvents extracts from lubricating oilfractions, the content of aromatic materials may vary from about 20% to100% by weight.

It is to be understood, accordingly, that the invention is broadlyapplicable to any petroleum fraction which contains at least about 20%by weight of reactable polynuclear aromatic hydrocarbons as hereindefined. These types of complex aromatic hydrocarbons are found in highconcentrations in solvent extracts obtained in the manufacture ofneutrals and bright stocks, all of which materials are to be understoodas suitable starting materials.

it is to be understood that the invention is particularly applicable toany solvent extract from the refining of mineral lubricating oils forthe purpose of separating nonarornatic and aromatic hydrocarbons, thatis, where the solvent exerts a preferential selectivity for thenonparaii-lnic constituents. The extracts are substantially freed ofsolvent, e.g., phenol extracts are dephenolized by steam stripping, sothat they contain practically no solvent.

in preparing the polybasic acids to be used in accordance with thisinvention, the starting solvent extract material is reacted first withan alkali metal in elementary form. For this purpose sodium, lithium,potassium, rubidium and cesium, and mixtures and alloys of these, may beused, that is, members of Group IA of the Periodic Chart of the Atoms,Hubbard, 1941, Revised Chart. About 30 parts of solvent extract are usedper 1 to 5 parts of alkali metal. The reaction may be carried out attemperatures as low as 60 C. and as high as 0 C. The prior art solventsfor this type of reaction, such as dimethyl glycol ether, dimethylether, methyl alkyl ethers, dialkyl glycol ethers, tetrahydrofuran, andtrimethylamine may be used.

The reaction of the alkali metal with the reactive complex aromaticcomponents does not occur unless steps are taken as shown in saidcopending application to overcome the effects of certain reactiveimpurities in the complex mixture which normally coat the sodium surfaceand prevent reaction. The undesirable reactive impurities present in themineral oil mixture may be traces of water, organic acids, mercaptansand other sulfur compounds, phenol, and other nitrogenoroxygen-containing compounds. The reaction can be advantageously effectedif fresh sodium surfaces are continuously exposed until all undesiredreaction impurities have reacted, or if sufficient sodium surface toreact with all such impurities plus a moderate excess is used. Anotherexpedient is to use a large excess of sodium metal. It appears that thatonce the undesired reactive impurities have reacted, the desiredreaction can take place on the excess clean sodium surface. It alsoappears that once the complex* ing reaction occurs, the oil solution ofcomplex begins to dissolve the undesired reaction product coating fromthe sodium surface, in effect cleaning the particle surface andrendering more surface available for reaction.

The reaction is diflicult to start unless an excess of sodium and freshsodium surface is used. Certain expedients have been found advantageous.Among these are continuous shearing of the sodium particles until thereaction starts. This has been accomplished with a Brookfieldcounter-rotating stirrer. Other shearing or crushing devices, such as aWaring Blendor, colloid mills, mullers, ball mills, and the like, alsomay be used. Even with continuous shearing or crushing, many minutes andsometimes hours are required before the desired complexing reactionstarts. The length of time required depends on the relative amounts ofundesired impurities present, and the sodium surface made available. Theinhibiting or dominating effect of the undesirable reactive impuritiesis one reason why petroleum hydrocarbon sources were not exploited asstarting materials for this type of reaction.

Another expedient found advantageous resides in the use of preformedsodium dispersion in an inert liquid. Such dispersions and theirpreparation are Well known in the art. According to said applicationSerial No. 819,932, a large excess of dispersed sodium must be used toinitiate the reaction, unless steps are taken to remove the coating ofundesired reaction products from the sodium surface. Suchsteps includethe use of mills.

Still another expedient, and the preferred one, is the actualpreparation of a sodium dispersion in the solvent extract to be reacted.The undesirable. impurities appear to completely react with the sodiumduring preparation of the dispersion, and as a consequence, clean sodiumsurface is available for the desired reaction as soon as the activeether is mixed with the sodium-reactive-component mixture. The desiredreaction then is practically instantaneous and proceeds smoothly andrapidly to completion with only a slight excess of sodium.

When the reaction with alkali metal is complete, as evidenced by itsdissolution, the reaction mixture is treated with carbon dioxide, eitherat about the same or a different temperature as was used during thereaction with alkali metal. The reaction mixture is next washed withwater and allowed to separate into a solvent phase and a water phase.Several applications of 1 volume of Water per 5 volumes of reactionmixture may be used and the water layers collected. Counter-currentwater-washing may be used. The resulting water phase is acidified withan acid such as a hydrohalic, sulfuric acid, or phosphoric acid. Thiscauses the polybasic, polynuclear aromatic acids to separate orprecipitate from the aqueous mixture.

Example I Broolcfleld counter-rotating stirrer and gas-inlet and -out-'let. The solution was cooled and maintained at l0-30 C. while 8.3 g. ofmetallic sodium in the form of cubes were added, after which cooling wasmaintained during a two-hour reaction period. No complex formationappeared to occur until approximately 25 minutes had elapsed.Thereafter, a strong color change was noted and the reaction appeared toproceed relatively rapidly.

After stirring for two hours, the mixture was cooled to 60 C. while anexcess of carbon dioxide gas was introduced. The color was discharged byreaction with carbon dioxide, but no precipitation was noted. Theunreacted sodium (5.1 g.) was removed, the tetrahydrofuran was strippedfrom the reaction mixture by applying a vacuum, after which theremaining liquid was combined with ether and washed with water.

The resulting aqueous phase was acidified and washed with ether torecover the free acids and other reaction products. About 89% W. of theoriginal oil feed stock was recovered, and about 11% had reacted to formthe acidic product of this invention. The product had an indicatedaverage molecular weight of 686 and a saponification value of 171. Thecalculated equivalent weight was 328 indicating 2.1 acid groups permolecule. However, the true average molecular weight probably wassomewhat lower than 686, the indicated average molecular weight beinghigher than actual because of molecular association in the benzenesolvent during its determination. Extract No. 18 of Table I was used inthis example.

EXAMPLE II 100 gms. of solvent extract and 675 ml. of drytetrahydrofuran were charged to a one-liter, 3-necked fiask equippedwith a stirrer, thermometer, pressure-equalized drop-funnel, gas-inletwith rotometer, and gas-outlet. A dry nitrogen atmosphere wasmaintained. Approximately 100 gms. of Alundum balls 7 diameter werecharged and agitation started. The solution was cooled to 20 C. and 8.3gms. of sodium as a 20% dispersion in toluene were added. After 5minutes, no reaction had occurred and the solution was allowed to warm.After minutes, the temperature had risen to 7 C. and a few particles ofsodium appeared to be reacting, i.e., the deep color of the complex wasseen to be forming on the surface of a few particles when agitation wasmomentarily stopped. Within an additional 17 minutes, the reaction wasproceeding smoothly and the dry carbon dioxide atmosphere was introducedto the flask in excess at l8 C. over a period of 78 minutes. Thereaction mixture was worked up as in the previous example after theexcess sodium was destroyed with water. Hydrogen evolution from theremaining sodium indicated that only 48% of the sodium had reacted.Approximately 84.5% of the oil was recovered, indicating 15.5% hadreacted. The acids recovered weighed 22.5 gms. and had a saponificationvalue of 241, indicating an equivalent weight of 233, and con tained2.8% sulfur. With a similar experiment, the acids recovered had asaponification value of 323, indicated 173 equivalent weight, with anindicated average molecular weight (cryoscopic) of 600. They contained3.0% sulfur. The ratio of molecular weight to equivalent weight was 3.4,indicating a mixture containing acids with more than 2 acid groups permolecule. Extract No. 18 of Table I was used in this example.

Suitable carrier liquids to form the initial mixture of alkali metal maybe any solvent which is non-reactive in relation to the alkali metal andwhich does not interfere with the reactions taking place. The filterpress used may be of the plate-and-frame type employing kieselguhr ordiatomaceous earth as the filter aid or filter means. The water used inthe process should be free of reactable salts and other impurities.Ordinary water-purification precautions applicable to organic synthesisshould be applied to insure against contamination of the end productsfrom this source. The hydrocarbon solvent used may be any liquid, orliquefiable, inert, aliphatic hydrocarbon. Propane, butane, heptane,octane, etc., may be used for this purpose of removing unreacted oilfrom the mixture. The

solvents used in stripper operations may be any ether or keton aving anappreciable solubility for the complex 8 acids product. Included in thiscategory are methyl ethyl ketone, diethyl ketone, acetone, methyl ether,diethyl ether, propyl ether, and dibutyl ether. Mixed ethers and ketonesare also useful. The acid used may be hydrochloric, sulfuric,phosphoric, and the like; non-mineral acids such as acetic andchloroacetic may also be used.

In operating the process on a continuous basis, solventextract oil andalkali metal are pumped through heat exchangers to a colloid mill wherethe alkali metal, in this case sodium, is dispersed in the reactantextract oil. The dispersion passes through a cooling heat-exchange intoa second colloid mill where is is intimately mixed with solvent (such astetrahydrofuran). The reaction mixture then passes through coolingheat-exchangers to mixingand carbonating-vessel where carbon dioxide isintroduced by means of a manifold. The carbonated solution is pumpedfrom reactor by means of a pump to a final carbonation zone where excesscarbon dioxide is injected under pressure.

The carbonated mixture then passes to a continuous rotary filter fromwhich unreacted sodium and other insoluble materials are removed, andthe filtrate passes in heat-exchange contact with the dispersion in anexchanger by means of a suitable chamber. The efiiuent from theexchanger passes to the top of tower wherein solvent is removed overheadand conveyed by a pump through heat exchangers and the chamber.

The residue is conveyed to a continuous extraction tower where water andether are introduced countercurrently. The hexane phase is stripped inanother tower to recover unreacted oil as bottoms. The ether iscondensed and conveyed to a second continuous extraction tower intowhich mineral acid (hydrochloric acid) and the alkaline extract from thecontinuous extraction tower are introduced countercurrently. The water(acidic) phase is discarded or treated for water recovery. The upperphase is stripped, whereby an overhead ether fraction is taken off, andthe polybasic product is recovered.

The dior polybasic polynuclear acids produced are mixtures of acidshaving aromatic nuclei of the naphthalene, phenanthrene and anthracenetype having several alkyl groups on each aromatic nucleus and whereinthe content of sulfur, nitrogen and oxygen is in the form ofheterocyclic rings associated therewith. The acids are more accuratelydescribed as dihydrocarboxylic acids since there is a change instructure with the introduction of the carboxyl groups. A verysimplified structure without showing the numerous alkyl substituents orthe heterocyclic nuclei and the relative percentage of each structuremay be:

where R comprises alkyl substituents having a sum of about 15 to 22carbon atoms in each formula, n is the number or" such alkyl group whichmay be from 3 to 10 and hetero illustrates one or more S, N, or 0containing heterocyclic rings in the molecule. The molecular weight ofthe acids ranges from 300 to 600 and the average from 325-450.

The following Table III gives the physical properties of typical extractdi-, or polybasic acids.

TABLE III Physical Properties of Extract Dibasic Acids Property: ValueAcid number 170-280 Melting points 80-90 C. Bromine No 16-24 Percentsulfur 1.7-2.3 Color Deep red Percent unsaponifiables 2-6 In order toillustrate the invention and the unusual effect of an inorganic salt andoxygen on the reaction, a series of examples is given.

EXAMPLE III A mixture consisting of 180 g. of extract dibasic acids, 50g. of glycerine, and 253 g. of dehydrated castor oil acids was placed ina resin kettle, equipped with watertrapped reflux condenser, and cookedat 450 F. under a blanket of nitrogen. The condensation reactionproceeded at a rate such that the acid number diminished to about 4 atthe end of about 2 hours. The bromine number of the resin was 39.

A portion of the resulting resin was dissolved in xylene and a film ofthe solution was placed on a sheet of tinplate and baked. During baking,the film de-wetted severely, i.e., it shrank into small islands on thetinplate, and was completely unsatisfactory as a coating.

EXAMPLE IV parent effect on the rate or course of the esterification atthe temperature used. The bromine number (a measure of the degree ofunsaturation in the polymer) was 39.

When the resulting resin was dissolved in xylene, coated onto tinplate,and baked, it also de-wetted and shrank severely. Thus, thisconventional technique does not produce a satisfactory alkyd resin fromextract dibasic acids.

EX MPLE v in accordance with this invention, a mixture of extractdibasic acids, glycerine, and dehydratedcastor oil acids having the samecomposition as the mixture of Example lli was placed in a resin kettle,1.26 g.'of ferric 10 29, indicating that some cross-linking had occurredduring the cooking period.

When a xylene solution of the resulting resin was prepared and a film ofthe solution baked on tinplate, a satisfactory alkyd resin film wasformed; no shrinking or dewetting was noted. Furthermore, the film driedin 20 minutes, as opposed to the slower rates noted with the resins ofExamples III and IV. The resin film was eminently satisfactory.

EXAMPLE VI The drying and baking properties of several alkyd resinsprepared from extract dibasic acids in accordance with this inventionwere determined to be as follows:

Free (Hours) 24 or more. 12.

2 These alkyds dried by solvent evaporation. Peutaeithritol was usedinstead of glycerine.

From these examples it is seen that the iron chloride and oxygen areessential. The properties of the resins are altered as desired byvarying the types and proportions of reactants, by varying the reactionconditions or by incorporating unsaturated fatty acids as modifiers andcombinations of the expedients. Additional alkyd resins of thisinvention were prepared in which the type of fatty acid, the type ofpolyol, and the polybasic extract acid concentration were varied. Also,other dibasic acids such as maleic anhydride and itaconic acid wereincorporated.

The following procedure was used for the preparations. The polybasicextract acid, fatty acid, and glycerine were put into a resin kettle. Todecrease the viscosity of the chloride hexahydrate 'were added, and themixture was cooked at 450 F. while a trace amount of oxygen wasmaintained in the nitrogen blanket inthe vapor zone of the'kettle. As inExamples III and IV, the condensation reaction proceeded at a rate suchthat the acid number of the mixture diminished to about 4 at the end ofabout 2 hours; the ferric chloride had no apparent effect on the rate ofesterification at the temperature employed. However, the bromine numberof the resulting resin was only molten resin and to promote the removalof water, xylene I was included. Heat was applied and agitation wasstarted as soon as the polybasic extract acid melted. A mixtureofnitrogen containing about 0.005 wt. percent of oxygen was introducedalong with about 0.05% by weight of iron chloride. As the temperaturereached 270 F., the xylene was removed continuously until thetemperature reached 450 F. When the acid number of the resin droppedbelow 5-6, the heating was discontinued and run was completed. Thefollowing table shows the results from several representative runs madeusing the extract polybasic acids prepared from extract oil No. 21(Table I).

TABLE IV Composition and Properties of EPA Alkyd Resins Composition 1Final Run Type 2 Acid Air-Drying Baking N0. Per- Per- Perof FA No. ofProperties Properties cent cent cent Resin EPA FA GL 50.2 14.1 DOO 5.550.6 13.5 DCO 5.0 18.1 70.5 11.3 DCO 2.7 27.4 60.9 11.7 DOO 5.5 46.441.3 12.3 DCO 5.0 55.0 32. 6 12. 3 DCO 4. 5 64. 0 22. 8 13. 0 D00 5.073.9 12.7 13.5 DCO 11.0 82.3 4.2 13.5 DOO 1.0 86.7 0.0 13.5 DOO 1.0

1 EPA=Extract Polybaeis Acid; FA=Fatty Acids; GL=Glycerine. 1DCO=Dehydrated Castor Oil Acid.

3 Maleic Anhydride was added to the EPA.

4 Itaconid Acid was added to the EPA.

In summary as seen from these experiments, we have found thatsatisfactory alkyd resins cannot be prepared from extract polybasicacids by conventional techniques wherein the polybasic acid is condensedwith a polyol by simple condensation under an inert atmosphere atelevated temperatures, even though a known esterification catalyst isused (paratoluenesulfonic acid) and/or temperatures as high as 450 F.are used. Such alkyd resins prepared by conventional techniques tend todc-Wet and eye-hole severely when baked on a metal surface. Such resinsare however useful for other purposes, but as wire or metal coatings andthe like they fail. We have also established that it is essential toconduct the condensation of the extract polybasic acid in the presenceof a metal salt and a small or trace amount of oxygen or air. The amountof metal salt required is small, being in the order of 0.01 to 1.0% byweight based on the weight of the total reaction mixture. The amount ofoxygen, from whatever source, is also small being only a trace amount,in the order of 0.001 to 0.1% by weight based on the weight of polybasicacids used.

The metal salt may be of any organic or inorganic acid as long as themetal is in its highest cationic valence state. Suitable metals includealuminum, antimony, arsenic, bismuth, cerium, chromium, cobalt, copper,gold, iron, lead, manganese, molybdenum, nickel, palladium, platinum,tin, titanium, vanadium, Zinc, and Zirconium. The anion may be ahalogen, nitrate, acetate, naphthenate, sulfonate, benzoate, bromidecarbonate, sulfate, lactate,

laurate, etc.

. Non-limiting examples are given as foHows, it being understood thatmixtures of the metal salts can be used:

Chromium nitrate. Chromium sulfate Cobalt nitrate Copper chloride Goldchloride Manganese bromide Nickel chloride Iron chloride Iron nitrateZinc acetate Palladium chloride Platinum chloride Tin bromide Titaniumchloride The species ferric chloride, ferric chloride hexahydrate,manganese chloride, cobalt nitrate, lead acetate, zinc naphthenate, andnickel sulfonate are preferred. Ferric chloride hexahydrate isparticularly effective.

The concentration of the metal salt used is so small that generally anyremaining salt or residue from the reaction does not interfere with theproperties of the resin with one possible exception. When the finishedresin is intended for use as an electrical insulating material, the saltif inorganic, must be insoluble in water or be of an acid which, whenreleased by hydrolysis, is volatile and distills from the reactionmixture at reaction conditions. This precautionary measure avoidscontamination of the resin with conducting ions which would adverselyaffect its insulating properties. In general, the salts used are similarto the so-called chemical driers which have been added to prior artalkyds after their preparation to accelerate their subsequent drying.Early addition of chemical driers is generally avoided in the prior artprocesses.

The invention is not to be limited by any theories of the roles playedby the metal salt and oxygen in the reaction of this invention. However,by way of partial explanation the metal salt and oxygen apparently causesufiicient cross-linking to create longer-chain polymers which, whenbaked, cross-link further and form a tough surface without significantshrinkage.

The alkyd resins of this invention have the general formula[OOCRCOOROOCRCOOROOCRCOO] wherein R is the residue of solvent extractsor reactable portion of solvent extracts characterized by complex,polynuclear high molecular weight cyclic structures, R is a hydrocarbonradical of a polyol, and x has a value of 2 to 8.

The polyhydric alcohols to be used to prepare the resins of thisinvention include any organic compounds having three or more hydroxylgroups in the molecule. Examplesof polyhydric alcohols are given asfollows:

The trihydric alcohols and higher polyhydric alcohols:

Glycerol Diglycerol Butantriol-l,2,3 The tetrahydric alcohols:

iErythritol and optically active forms thereof Pentaerthn'tol Thepenta'hydric alcohols (CH OH(CHOH) CH OH) and isomers thereof:

Adonitol The riboses dand l-Arabitol Xylitol oxygen.

13 The hexahydric aclohols (CH OHWHOHMCH OH):

Dipentaerythritol d-Mannitol d-Sorbitol d-Iditol Dulcitol Theheptahydric alcohols:

Perseitol Volernitol The fatty acids used in accordance with thisinvention as modifiers include the saturated and unsaturated fatty acidsand their mixtures from such sources as:

Animal fats and oils:

Butter fat Lard Neats-foot Tallow (beef) Tallow (mutton) Marine fats andoils:

Herring Menhaden Sardine V Sperm (body) Sperm (head) Whale The foregoingare sources of such saturated fatty acids as caproic, caprylic, capric,lauric, myristic, palrnitic, stearic, arachidic, behenic and lignocericacids, that is saturated fatty acids having from 6 to 24 carbon atoms.The unsaturated fatty acids include lauroleic, myristoleic, palnitoleic,oleic, gadoleic, erucic, ricinoleic, linoleic, linolenic, eleostearic,licanic, arachidonic and clupanodonic acids to include those having from12 to over 26 carbon atoms per molecule. Rosin acids, conjugated acids,hydroxy acids and terpenic acids in this series are also included. Thehydrogenated and dehydrated forms thereof are intended as reactants forthe preparation of the resins of this invention. A preferred species ofthe dehydrated castor oil fatty acids contains about 2% palmitic acid,about 1% stearic acid, about 7% oleic acid, about 87% ricinoleic acid,and about 3% linoleic acid. Dehydrated corn oil acids, dehydratedhempseed acids, and dehydrated cottonseed acids may also be used.

In preparing the alkyd resins of this invention, any of the knownesterification procedures may be used as modified by incorporating 0.01to 1.0% by weight ofv a metal salt along with 0.001 to 0.10 weightpercent of Both the metal salt and oxygen mustjbe presem to obtain theresults of this invention. If the reaction is carried out without oxygenbeing present, the resin product is not sufficiently cross-linked. Thereaction may be carried out in the usual manner by refiuxing thepolybasic extract acid (EPA) and polyol with a small amount of metalsalt, fatty acid, oxygen, or air. The equilibrium is shifted to theright by an excess of one of the reactants or by the removal of water,either by azeotropic distillation or by flowing an inert gas through thehot mixture during reaction. The reaction takes place with mostpolyhydric alcohols at temperatures between about 70 F. to 500 F. usingatmospheric or superatmospheric conditions. Because the methods ofesterification applicable to the reaction herein are well known, thereis no necessity for further description.

By collecting the Water produced during the reaction, and plotting thevolume thereof against time, the course of the esterification can befollowed. Applying this principle to Run No. 12 of Table IV showed thatthe reaction proceeded easily without a catalyst and reached equilibriumin about 180 minutes. This was comparable to the reaction of phthalicanhydride and glycerol and showed the poiybasic extract acids to beabout as reactive as phthalic anhydride.

As in the case of phthalic alkyd resins, gelation may occur if thepolybasic extract acids are present in amounts above about 45%. Thesegels are infusible and insoluble in any solvent. An unmodified alkydresin was made with a polybasic extract acid content of 94.7%. Thisresin was fluid when hot, and hard and brittle at room temperature, butwas still soluble in xylene. In the case of modified alkyd resins madefrom polybasic extract acids, the viscosity of the alkyd increases withincreasing polybasic extract acid content. Above a polybasic extractacid content of about 64%, the resins are hard and brittle.

The polybasic extract acids, from which the resins of this invention aremade, are solid, dark, glossy materials having an unpleasant odor. Theresins prepared therefrom are practically odorless. During theesterification, 29 g. of a yellow oil was collected which had a veryunpleasant odor. The oil was analyzed by infrared spectroscopy and foundto be mostly saturated ketones, probably in the C -C range.

Because of their unique chemical and physical properties, the alkydresins of this invention have many uses, such as wire coatings, waterresistance films formation, baked enamels, adhesives, and similarapplications. The properties of the resin and the coating, film, orother product produced therefrom, are subject to control depending onthe polybasic extract acid content of the resin, the fatty acid modifierused, the type of drying agent present, the conditions of baking, andother factors. Some of these properties and other advantages of theresins are illustrated as follows.

Our resins possess satisfactory air-drying properties (with theincorporation of chemical driers) when they contain about 35-70% w. ofthe mixed dibasic acids, 15-50% W. of an unsaturated fatty acid, and aneutralizing amount of a polyol. Resins having these compositions havesatisfactory bake-drying properties even without chemical driers. Butwhen less than about 35% w. of the mixed dibasic acid is used, the resinshrinks during drying and forms an unsatisfactory film. When more thanabout 70% w. dibasic acid, and less than about 15% w. of fatty acid, isused, the air-drying rate is diminished in proportion to the reductionin fatty acid content, but because the resulting alkyds are soluble inaromatic solvents, they are useful as coatings which dry by solventevaporation". It is to be noted, however, that the air-drying rate ateven these low fatty acid contents can be increased significantly byincorporating a small amount of any of the known chemical drying agents,

such as metal naphthenates. The drying properties of our resins may besummarized as follows:

TABLE V Dibasie Acid Fatty Acid Chemical Drying Mechanism Content*Content* Drier 40-70%w 45-15% W Yes Air-drying. 40-70% w 45-15% w. NoBake-drying. 70-85%w 150%w No Evaporation-drying.

*In accordance With common alkyd resin terminology, the proportions ofdibasic acid and unsaturated fatty acid are stated as percentages of thefinal resin. The balance to 100% is polyol.

For film casting, the resins were diluted with xylene. The originalviscosity of several polybasic extract acid alkyds and the viscosity ofthe 70% alkyd solution are given in Table VI.

TABLE VI Viscosity of Alkyd Resins Original Vis- Vis. f the Polybasieextract acid content of the Resin cosity 70/30 Xylene (Stokes) Solution(Stokes) Solid 0.27 148 2. 25 0 98. 0. 65 20% 5.0 0. 50

To evaluate the resins for hardness and drying time the Sward hardnessrocker was used. The device consists of a rocker and an electroniccounting mechanism. A panel coated with the resin is placed on a table;the rocker is put on the panel and released. The swinging of the rockerinterrupts a light beam and the number of oscillations is countedautomatically. The results can be given in two ways:

(1) For hard films: The number of oscillations above a fixed amplitude(Sward hardness).

(2) For soft films: The number of seconds until the rocker comes tocomplete rest (Rocking time).

The second method is more sensitive and consequently is used most often.The harder the resin film, the longer is the rocking time. Evaluation ofresins #2 and #6 is shown in Table VIII.

TABLE VIII Drying Rocking Resin N 0. Fatty Acid Type Time Time (hrs)(sec) The air-drying and baking properties of modified alkyd resinsdepend upon the amount and position of the double bonds in the fattyacid portion of the alkyd molecule. Since the polybasic extract acidsare only slightly unsaturated (Bromine Number=18-22), the unsaturatedfatty acids used as modifiers contributed most to the resinunsaturation. Despite the act that the linoleic acid has the same degreeof unsaturation (Br No. 99) as the dehydrated castor oil (Br No; 97)acid, the latter imparts better drying properties because 30% of itsdouble bonds are conjugated. The comparison in drying time of resinsmade with these two acids is also given in Table VII. In 75 15 bothresins the polybasic extract acid content was 36.5% (Runs #2, 6 in TableVII) and 0.2% cobalt naphthenate was added to promote drying.

Modified alkyd resins #14 and #15, made with dehydrated castor oilacids, using 55% and 64% polybasic extract acids respectively wereevaluated on the Sward hardness rocker. The results are shown in TableVIII:

TABLE VIII 10 Air Drying Propertzes w/ 0 Drying Agent Test RockingDrying N 0. Resin No. Time Time (secs) (hrs) #14 (Polybasic Acid content55.0% 3.0 5.0 2 do 3.0 20.0 3. 0 140.0 3. 0 280.0 3. 0 490. 0 3. 5 640.0 18.0 765.0 43. 0 1. 0 50. 0 20. 0 96. 0 140.0 87.0 280.0 105. 0 495. 0100. 0 625.0 83.0 700. 0

The results are divisible into two parts. Above 64% polybasic extractacid content the resins are solids. As soon as the solvent hadevaporated, a tack-free film resulted. Consequently, the tests No. 8 and9 for resin #15 represent the change that takes place during drying bysolvent evaporation, or so-called apparent air-drying. The film soformed consists of high-molecular-weight, unsaturated polymers whichreact further and cross-link at a slow rate. This is represented by thechanges taking place from test No. 9 to test No. 13, or so-called actualair-drying.

The resins with 55% or lower polybasic extract acid content, asrepresented by resin No. 14 did not air-dry and were still tacky after500 hours. The films with 64% or more polybasic extract acid content, asrepresented by resin No. 15, were of poor quality, low mar-resistance,and exhibited poor adhesion.

As a result of these tests, resin No. 6 was evaluated in the Swardhardness rocker with a drier being used in the preparation of the testfilm. These results are shown in Table IX.

TABLE 1X Air Drying Properties With A Drier [Resin N0. 6]

Test; Rockin Dr N o. Drying Agent Time Ti r h ie (secs) (hrs) CobaltNaphthenatc (0.05% 00) 2. do 4. 18. 24. 41. 60. .118.

The use of a combination of cobalt naphthenate (0.10%

Co) and calcium naphthenate (0.5% Ca), the latter having little or nodrying action by itself and termed an auxiliary drier, in resin No. 6decreased the drying time to 22 hours to attain a rocking time of 51seconds. At 74 hours the rocking time was 64 seconds, and at 166 hoursthe rocking time was 73 seconds, using the combination of cobaltnaphthenate and calcium naphthenate in No. 6 resin.

The effect of baking time and temperature upon the hardness of the resinfilms formed from resin No. 6 was evaluated using the Sward hardnessmachine. The resin films baked rapidly and exhibited no filmdiscontinuities (eyeholes, craters, etc.). Preliminary tests revealedthat with increasing polybasic extract acid content, the flexibility andadhesion of the film decreased. Although the prior art teaches the useof various driers, and it is common to use 0.1 to 0.2 wt. percent ofzinc and/ or 0.005 to 0.01 wt. percent cobalt in forming baked films,the resins of this invention form high-quality baked films without theuse of any drier other than the iron present in the polybasic extractacids.

Infrared analyses of the resin films at intervals during the bakingperiod were made to follow the chemical changes taking place. Theseanalyses revealed that the chemical changes were influenced more by thevariation in film thickness than by the baking time. With increasingbaking time, the number of conjugated double bonds decreased and thelowest value was attained after 15 minutes of baking. The infraredanalyses revealed that cross-linking with -C-O-C- bonds was takingplace, these bonds attained a maximum concentration in 15-20 minutes ofbaking time, and that the concentration then decreased. In the firstfifteen minutes of baking there was an increase in carbonyl and hydroxylgroups in the film.

fost of the chemical changes occurred within the first 35-40 minutes ofbaking.

The influence of the baking schedule on the physical properties of thealkyd resins of this invention was also evaluated. Various films werecast at 1 mil wet thickness, which after baking produced films of 0.4 to0.5 mil dry thickness. The results of a series of tests on resin No. 6are shown in Table X.

TABLE X Efiect Baking Time and Temperature Upon Film Hardness [Resin No.6]

The data in Table X was checked with duplicate samples at the indicatedtemperatures and close ag eement was obtained. The optimum baking timeand temperature for resin No. 6 was determined to be about 60 minutes atabout 160 C.

The resins of this invention exhibit high chemical resistance,particularly in the form of baked films. Bakedfilm strips on variousmetal and glass surfaces were prepared, and the test strips wereimmersed in cold Water, salt water, kerosene, xylene and detergent forone week. None of the test strips showed any change except thoseimmersed in xylene which showed a slight softening of the film at theend of the test period. However, after being removed from the Xylenethese test strips recovered their original hardness after 20-30 minutesin con- 18 tact with the air. These tests indicated that chemicalresistance was influenced by the curing or baking time and bestresistance was obtained at baking times of about 30 minutes to 1 hour atto C.

Further tests showed that the flexibility and adhesion of the air-driedand baked films, as measured on a conical mandrel and impact tester, wasa function of the poly basic extract acid content of the resin. Increasein the polybasic extract acid content decreased the toughness,flexibility and adhesion, and increased the hardness of both theair-dried and baked films. At a polybasic extract acid content of40-70%, the air-dried and baked films exhibited the highest degree ofhardness and flexibility. Soft films were formed of resins having apolybasic extract acid content of below 40% and above 69% acid content.The films began to show brittleness and resembled the properties of thepolybasic acids themselves. Resins having 64% to 70% acid content,however, were found to exhibit desirable adhesion and toughness, makingthem useful for many purposes. The resins having an acid content ofbelow 40% find utility as caulking compounds, ingredients for plasticcements and marine glue.

The air-dried and baked films formed from the resins of this inventionfind utility as wire enamels or coatings because of their electricalresistance as measured by the dielectric strength and dielectricconstant. The dielectric strength of an insulator is the voltage whichmust be applied to cause an are or spark discharge through the resinfilm or insulator. This value is expressed in volt/mils and is afunction of the film thickness. The dielectric constant is a measure ofthe ability of a material to store electrostatic field energy in thepresence of an electrical field. In a given capacitor, using the resinor material as a dielectric, a high dielectric constant indicates a highelectrostatic capacity. Table XI gives the dielectric strength anddielectric constant of some known plastics and insulators in comparisonwith resin No. 6.

Thickness (mils) Dielectric Strength Dielectric Constant at 103 cyclesPlastic Polyvinyl chloride The alkyd resins of this invention can beobtained in various forms depending on the type of drying propertiesdesired. Furthermore, satisfactory alkyds can be obtained, as a featureof the invention, with much less fatty acid modifier than is required inmaking phthalic acid or maleic acid alkyd resins. The alkyd resins ofthis invention have been shown to form satisfactory drying films, byestablished criterion known in this art, when their fatty acid contentis as low as about 15% based on the total resin weight, incontradistinction with prior art alkyds requiring at least about 30%fatty acid content. Also, even when the alkyd resins of this inventioncontain less than about 15% fatty acid, to the point of being free offatty acid modifier or any modifier, they are soluble in a wide range ofinexpensive, connnercially-available aromatic solvents, and as such, areuseful as film-forming coatings which dry primarily through solventevaporation. On the other hand, alkyds prepared from the dibasic acidsand anhydrides used in the prior art are insoluble in practically allsolvents when less than about 30% of a fatty acid modifier is used, andare not suitable for use in coating compositions. Our resins are furtherdistinguished from prior art alkyds in that they contain fewer esterlinkages per polymer chain than the prior art alkyds, and consequentlyare more resistant to attack by alkaline and acidic environments. Theprimary function of the fatty acid is to react with part of the polyolhydroxy groups to plasticize therein and impart air-drying abilitythereto.

It is seen that the alkyd resins of this invention have properties whichare equal to and in some instances superior to prior art alkyd resins.Having thus described the invention, the only limitations attachingthereto appear in the appended claims wherein R is intended to besynonymous with the portion of solvent extracts reactable with alkalimetals followed by reaction with carbon dioxide and acidification toform dior polybasic acids and is composed of compounds characterized bycomplex, polynuclear, aryl, alkaryl, and/ or heterocyclic nuclei. The Rnuclei has attached to it at least one carboxyl group reactable with apolyol to form an ester. Although some of the individual ester moleculesin the product may comprise simple esters, the main portion of the esteror mixture of esters and polyesters persent have 2, 3 or moreRCOO-groups and also 2 or more R groups from the polybasic nature of theacids and the polyhydroxy nature of the alcohols. The terms residue ofsolvent extracts and reactable portion of solvent extracts have beenused synonymously herein to mean the complex organic portion of theextracts in the products resulting from metalation, carbonation, andacidification, in accordance with the processes of application SerialNumber 819,932 and exclusive of the carboxyl groups. The process andproducts herein described are an improvement over the process andproducts of application Serial Number 55,123, filed September 12, 1960.

The embodiments of the invention, in which an exclusive property orprivilege is claimed, are defined as follows:

1. The method of preparing alkyd resins comprising reacting:

(1) Complex carboxylic acids prepared from solvent extracts obtained inthe solvent refining of mineral lubricating oils using a solventselective for aromatic compounds, by reaction of said solvent extractswith 233 an alkali metal to form the alkali metal adduct, carbonation ofsaid adduct to form the corresponding alkali metal salt of a carboxylicacid said carboxylic acids being characterized by having complexpolynuclear, aromatic, alkyl-aromatic and heterocyclic nucleipredominating in carbon and hydrogen, containing about 1.9 to 4.5% byweight of combined sulfur and also containing oxygen and nitrogen,having an average molecular weight of about 320 to 750, and having about1.7 to about 3.5 aromatic rings per mean aromatic molecule andacidification of said salt to form the free acid, and

(2) A polyol having 3 to 20 carbon atoms to the molecule and 3 to 7hydroxyl groups to the molecule in the presence of about 0.01 to 1.0% byWeight of a metal salt of the group consisting of ferric chloride,ferric chloride hexahydrate, manganese chloride, cobalt nitrate, leadacetate, zinc naphthenate and nickel sulfonate and blanketing saidreactants with an inert gas containing as the sole oxidizing agent about0.001 to 0.1% by weight of oxygen based on the weight of said complexcarboxylic acid.

2. The method in accordance with claim 1 in which about 40% to 70% bywt. of said complex carboxylic acid and to 15% by weight of a fatty acidare reacted.

3. The method in accordance with claim 1 in which said reaction isconducted at a temperature of about 450 F. and said salt is ferricchloride.

References Cited in the file of this patent UNITED STATES PATENTS2,585,323 Elwell et al Feb. 12, 1952 2,734,879 Lyons Feb. 14, 19562,739,902 Mack et al. Mar. 27, 1956 2,823,197 Morris et al Feb. 11, 19582,970,164 Jezl Jan. 31, 1961 2,971,932 Rickert Feb. 14, 1961 3,057,824Le Bras et al Oct. 9, 1962 OTHER REFERENCES Chatfield: VarnishConstituents, 3rd Edition, Leonard Hill Limited, London, 1953, pages 281and 282.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION- Patent No.3,154,507

It is hereby certified. that October 27, 1964 Walter E. Kramer et a1,

error appears in the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column 11, read Polybasi-c read Table VII "TABLE VIII" read for "act"read Signed and SEAL Attest:

ERNEST w. SWIDER' Attesting Officer TABLE IV, footnote 1 thereof, for"Polybacis" column 15, line 46 for "Table VIII" line 47, for thecentered heading TABLE VII same column l5 line 70,

fact

sealed this 16th day of March 1965.

EDWARD-J. BRENNER Commissioner of Patents

1. THE METHOD OF PREPARING ALKYD RESINS COMPRISING REACTING: (1) COMPLEXCARBOXYLIC ACIDS PREPARED FROM SOLVENT EXTRACTS OBTAINED IN THE SOLVENTREFINING OF MINERAL LUBRICATING OILS USING A SOLVENT SELECTIVE FORAROMATIC COMPOUNDS, BY REACTION OF SAID SOLVENT EXTRACTS WITH AN ALKALIMETAL TO FORM THE ALKALI METAL ADDUCT, CARBONATION OF SAID ADDUCT TOFORM THE CORRESPONDING ALKALI METAL SALT OF A CARBOXYLIC ACID SAIDCARBOXYLIC ACIDS BEING CHARACTERIZED BY HAVING COMPLEX POLYNUCLEAR,AROMATIC, ALKYL-AROMATIC AND HETEROCYCLIC NUCLEI PREDOMINATING IN CARBONAND HYDROGEN, CONTAINING ABOUT 1.9 TO 4.5% BY WEIGHT OF COMBINED SULFERAND ALSO CONTAINING OXYGEN AND NITROGEN, HAVING AN AVERAGE MOLECULARWEIGHT OF ABOUT 320 TO 750, AND HAVING ABOUT 1.7 TO ABOUT 3.5 AROMATICRINGS PER MEAN AROMATIC MOLECULE AND ACIDIFICATION OF SAID SALT TO FORMTHE FREE ACID. AND (2) A POLYOL HAVING 3 TO 20 CARBON ATOMS TO THEMOLECULE AND 3 TO 7 HYDROXYL GROUPS TO THE MOLECULE IN THE PRESENCE OFABOUT 0.01 TO 1.0% BY WEIGHT OF A METAL SALT OF THE GROUP CONSISTING OFFERRIC CHLORIDE, FERRIC CHLORIDE HEXAHYDRATE, MANAGANESE CHLORIDE,COBALT NITRATE, LEAD ACETATE, ZINC NAPHTHENATE AND NICKEL SULFONATE ANDBLANKETING SAID REACTANTS WITH AN INERT GAS CONTAINING AS THE SOLEOXIDIZING AGENT ABOUT 0.001 TO 0.1% BY WEIGHT OF OXYGEN BASED ON THEWEIGHT OF SAID COMPLEX CARBOXYLIC ACID.